JP4941328B2 - Continuously variable transmission - Google Patents

Description

  This invention is for generators (generators) used in, for example, automatic transmissions for vehicles (automobiles), automatic transmissions for construction machines (construction machinery), aircrafts (fixed wing aircraft, rotary wing aircraft, airships, etc.), etc. The present invention relates to an improvement of a continuously variable transmission used as an automatic transmission or the like. Specifically, the pressure oil introduced into the pressing device is also introduced into the clutch device, so that this clutch device is connected, and an appropriate pressing force is secured at the traction part (rolling contact part) that transmits power. However, the structure which can ensure the fastening pressure of the said clutch apparatus which should be connected is implement | achieved.

  The use of a toroidal continuously variable transmission as a vehicle (automobile) transmission is described in, for example, many publications and is well known in some implementations. Also, a continuously variable transmission that combines a toroidal continuously variable transmission and a differential unit (for example, a planetary gear transmission that is a gear-type differential unit) in order to increase the fluctuation range of the transmission ratio is disclosed in, for example, a patent. Conventionally, it is widely known, for example, as described in Documents 1 to 4. Among these, Patent Documents 1 and 2 describe a mode in which power is transmitted only by a toroidal-type continuously variable transmission (low-speed mode), and main power is transmitted by a planetary gear type transmission that is a differential unit. A continuously variable transmission having a mode (high speed mode) that realizes a so-called power split state in which a gear ratio is adjusted by a continuously variable transmission is described. Further, in Patent Documents 3 to 4, a mode that can realize a so-called geared neutral state in which the rotation state of the output shaft can be switched between normal rotation and reverse rotation with the input shaft rotated in one direction. A continuously variable transmission with (low speed mode) is described.

  FIGS. 12-13 has shown the continuously variable transmission provided with the mode which can implement | achieve the geared neutral state described in patent documents 3-4. Of these, FIG. 12 shows a block diagram of the continuously variable transmission, and FIG. 13 shows a hydraulic circuit for controlling the continuously variable transmission. The output of the engine 1 is input to the input shaft 3 via the damper 2. The power transmitted to the input shaft 3 is transmitted directly or via a toroidal type continuously variable transmission 4 to a planetary gear type transmission 5 that is a differential unit. The differential components of the constituent members of the planetary gear type transmission 5 are taken out to the output shaft 9 via the clutch device 6, that is, the low speed and high speed clutches 7 and 8 shown in FIG. The toroidal-type continuously variable transmission 4 has input and output disks 10 and 11 corresponding to the first and second disks, respectively, and a plurality of power rollers 12, each corresponding to a support member. A plurality of trunnions (not shown), an actuator 13 (FIG. 13), a pressing device 14, and a transmission ratio control unit 15.

  Of these, the input-side and output-side disks 10 and 11 are arranged concentrically and relatively freely rotatable. Each of the power rollers 12 is sandwiched between the inner surfaces of the input and output disks 10 and 11 facing each other, and the power roller 12 is driven between the input and output disks 10 and 11. (Force, torque) is transmitted. Each trunnion supports each power roller 12 rotatably. The actuator 13 is of a hydraulic type, and the trunnions supporting the power rollers 12 are displaced in the axial directions of the pivots provided at both ends so that the input side disk 10 and the output side The gear ratio with the disk 11 is changed. The pressing device 14 is of a hydraulic type that generates a pressing force proportional to the hydraulic pressure with the introduction of the hydraulic pressure, and presses the input side disk 10 and the output side disk 11 in a direction approaching each other. . The gear ratio control unit 15 controls the displacement direction and the displacement amount of the actuator 13 so that the gear ratio between the input side disk 10 and the output side disk 11 becomes a desired value.

  In the case of the illustrated example, the transmission ratio control unit 15 includes a controller (ECU) 16, a stepping motor 17 that is switched based on a control signal from the controller 16, a line pressure control electromagnetic on-off valve 18, and the like. The solenoid valve 19, the shift solenoid valve 20, and the control valve device 21 whose operation state can be switched by these members 17 to 20. The control valve device 21 includes a transmission ratio control valve 22, a differential pressure cylinder 23, correction control valves 24a and 24b, and high-speed clutch and low-speed clutch switching valves 25 and 26 (FIG. 13). It is a combination. Of these, the gear ratio control valve 22 controls the supply and discharge of hydraulic pressure to the actuator 13. Further, the differential pressure cylinder 23 is configured to control the transmission ratio control valve so as to correct the transmission ratio of the toroidal type continuously variable transmission 4 according to the force (passing torque) passing through the toroidal type continuously variable transmission 4. This is for adjusting the switching state of 22. The correction control valves 24 a and 24 b control the supply and discharge of pressure oil to and from the differential pressure cylinder 23. Further, the switching valves 25 and 26 for the high speed clutch and the low speed clutch switch the introduction state of the pressure oil to the low speed and high speed clutches 7 and 8, respectively.

  Further, the pressure oil discharged from the oil pump 27 (27a, 27b in FIG. 13) driven by the power extracted from the damper 2 is sent to the control valve device 21, the pressing device 14, and the like. That is, the pressure oil sucked from the oil reservoir 28 (FIG. 13) and discharged by the oil pumps 27a and 27b is adjusted to a predetermined pressure by the pressure adjusting valve 29 and the low pressure side adjusting valve 30 (FIG. 13). It is free. Of these adjusting valves 29 and 30, the pressing force adjusting valve 29 for adjusting the hydraulic pressure sent to the pressing device 14 and the manual hydraulic pressure switching valve 31 is described in detail in, for example, Patent Document 5 and the like. In addition, it has a function as a relief valve, and includes first to third pilot portions 32 to 34. Of these, the first and second pilot portions 32 and 33 control the opening pressure of the pressing force adjusting valve 29 according to the magnitude of the force (passing torque) passing through the toroidal-type continuously variable transmission 4. It is for adjusting. For this purpose, there exists between a pair of hydraulic chambers 36a and 36b provided with a piston 35 sandwiched between an actuator 13 for displacing a support member (trunnion) for supporting the power roller 12 in the axial direction of the pivot axis. A hydraulic pressure difference (differential pressure) is introduced into the first and second pilot parts 32 and 33 via a differential pressure take-out valve 37.

  On the other hand, the third pilot portion 34 is a transmission ratio of the toroidal type continuously variable transmission 4, the temperature of the lubricating oil (traction oil) existing in the toroidal type continuously variable transmission 4, and a drive source. This is for adjusting the valve opening pressure of the pressure adjusting valve 29 according to operating conditions other than the passing torque (corresponding differential pressure) such as the rotational speed of a certain engine 1. That is, the valve opening pressure of the pressure adjusting valve 29 is adjusted according to the magnitude of the passing torque (corresponding to the differential pressure) (adjusted by the first and second pilot parts 32 and 33). The value is adjusted (depressurized) to a target value corresponding to the optimum pressing force to be generated by the pressing device 14 in accordance with operating conditions other than this passing torque (the corresponding differential pressure). For this purpose, pressure oil of a predetermined pressure is introduced into the third pilot portion 34 based on the opening / closing (duty ratio control) of the line pressure control electromagnetic switching valve 18 controlled by a command from the controller 16. Yes. Then, by appropriately adjusting the hydraulic pressure introduced into the first to third pilot parts 32 to 34, {according to the magnitude of the passing torque (differential pressure) in the first and second pilot parts 32 and 33 By introducing the hydraulic pressure and introducing the hydraulic pressure adjusted based on the command of the controller 16 to the third pilot section 34, the opening pressure of the pressing force adjusting valve 29, and thus the pressing device The pressing force generated by 14 is appropriately regulated in accordance with the operation status of the toroidal type continuously variable transmission 4.

  For example, FIG. 14 shows the relationship between the opening of the line pressure control electromagnetic on-off valve 18 (percentage of the open time per unit time) and the amount of pressure reduction (the amount of decrease in the valve opening pressure of the pressure adjusting valve 29). An example is shown. Based on such a relationship, the controller 16 adjusts the opening / closing of the line pressure control electromagnetic on / off valve 18 (duty ratio control), thereby opening the pressure of the pressing force adjusting valve 29, and thus the pressing pressure. By adjusting the hydraulic pressure introduced into the device 14 to the target value, the pressing force generated by the pressing device 14 is appropriately regulated. In the case of the illustrated example, the pressure adjusting valve 29, the differential pressure extracting valve 37, the controller 16, and the line pressure controlling electromagnetic on-off valve 18 are hydraulic pressure adjusting means described in the claims. It corresponds to.

  Further, the pressure oil adjusted by the pressing force adjusting valve 29 is supplied to the low speed clutch via the manual hydraulic pressure switching valve 31, the pressure reducing valve 38, the high speed clutch switching valve 25 or the low speed clutch switching valve 26. The clutch 7 or the high-speed clutch 8 can be fed into the hydraulic chamber. The low speed clutch 7 out of the low speed and high speed clutches 7 and 8 is connected when realizing a low speed mode in which the reduction ratio is increased (including an infinite gear ratio (including a geared neutral state)). At the same time, the connection is broken when the high speed mode for reducing the reduction ratio is realized. In contrast, the high speed clutch 8 is disconnected when realizing the low speed mode and is connected when realizing the high speed mode. Further, the supply / discharge state of the pressure oil to the low speed and high speed clutches 7 and 8 is switched according to the switching of the shift solenoid valve 20.

  FIG. 15 shows an example of the relationship between the speed ratio (speed increase ratio) of the toroidal-type continuously variable transmission 4 and the speed ratio (speed increase ratio) of the continuously variable transmission as a whole. For example, in the low speed mode in which the low speed clutch 7 is connected and the high speed clutch 8 is disconnected, the transmission ratio of the toroidal continuously variable transmission 4 can be realized in the GN state as indicated by the solid line α. As the speed is decelerated from the value (GN value), the speed ratio of the continuously variable transmission as a whole is increased from the stopped state (speed ratio 0 state) to the forward direction (+: forward rotation direction). Similarly, as the speed increases from the GN value, the speed is also increased in the backward direction (-: reverse direction) from the stopped state. On the other hand, in the high speed mode in which the high speed clutch 8 is connected and the low speed clutch 7 is disconnected, as indicated by the solid line β, the speed ratio of the toroidal continuously variable transmission 4 is increased. The speed ratio of the continuously variable transmission as a whole can be increased (in the forward direction).

  In general, “speed ratio” is a reduction ratio, “speed ratio” is an increase ratio, and the reciprocal of “speed ratio” is “speed ratio” (“speed ratio” = 1 / “ Gear ratio "). However, in the present specification and claims, the term “speed ratio” is used for the ratio between the input side and the output side for the toroidal type continuously variable transmission, and the input side for the entire continuously variable transmission is The term “speed ratio” is used for the ratio to the output side. The reason for this is to make it easy to clarify whether it is the ratio of the toroidal type continuously variable transmission or the ratio of the continuously variable transmission as a whole. Therefore, in the present specification and claims, the “speed ratio” does not necessarily correspond to the reduction ratio, and the “speed ratio” does not necessarily correspond to the speed increase ratio.

  In a vehicle incorporating a continuously variable transmission as described above, based on the vehicle's current driving condition (driving condition) obtained from the accelerator pedal operation (accelerator opening) and the vehicle's driving speed (vehicle speed). The controller 16 obtains the optimum speed ratio (target speed ratio) of the continuously variable transmission. Then, in order to realize this target speed ratio, the stepping motor 17 is driven based on the control signal of the controller 16 and the speed ratio control valve 22 is switched, so that the speed ratio of the toroidal type continuously variable transmission 4 is The target speed ratio corresponding to the target speed ratio is adjusted. In addition, by switching the shift solenoid valve 20 as necessary (in accordance with the target speed ratio of the continuously variable transmission), the connection state of the low speed and high speed clutches 7 and 8 is switched. Select the required travel mode (low speed mode or high speed mode). Thus, the speed ratio of the continuously variable transmission is adjusted to an optimum value (target speed ratio) according to the running state of the vehicle at that time.

  By the way, the toroidal continuously variable transmission 4 and the planetary gear type transmission 5 as described above are combined through the clutch device 6 (7, 8), and the low speed mode (first mode) and the high speed mode ( In the case of the continuously variable transmission having the second mode), the above-described geared neutral state can be realized, or the power split state as described in Patent Documents 1 and 2 can be realized. Smooth switching of the mode at the time of switching between the low speed mode and the high speed mode is important from the viewpoint of ensuring ride performance (good ride quality) and durability. As a technique for smoothly performing such mode switching, for example, Patent Document 6 describes a technique for simultaneously connecting a clutch that has not been connected and a clutch that has been connected so far when the mode is switched. Has been. By adopting such a technique, for example, when the mode is switched during acceleration, it is possible to prevent a sudden increase in engine speed due to the simultaneous disconnection of both the low speed clutch and the high speed clutch. Further, it is possible to prevent a shift shock (a feeling of torque loss and a feeling of pushing out) that accompanies the connection of the high speed clutch after the sudden rise, and it is possible to prevent the driver and other passengers from feeling uncomfortable. Further, it is possible to reduce the impact applied to each component when the mode is switched, and to secure durability.

  In the case of the continuously variable transmission shown in FIGS. 12 to 13 described above, the pressing force generated by the pressing device 14 is adjusted in accordance with the torque (passing torque) passing through the toroidal continuously variable transmission 4. In addition, the hydraulic pressure corresponding to the hydraulic pressure difference (differential pressure) between the pair of hydraulic chambers 36a and 36b constituting the actuator 13 is adjusted (via the differential pressure extracting valve 37). It is introduced into the first and second pilot chambers 32, 33). On the other hand, instead of such a structure in which the differential pressure is directly introduced into the pressing force adjusting valve 29, hydraulic sensors 39a and 39b (39 in FIG. 12) provided in the pair of hydraulic chambers 36a and 36b constituting the actuator 13, respectively. It is also conceivable to detect the differential pressure by adjusting the pressure generated by the pressing device 14 based on this differential pressure (or the passing torque obtained from this differential pressure). When such a configuration is employed, the hydraulic pressure chambers 36a and 36b constituting the actuator 13 and the pressing force adjustment valve 29 are communicated with each other as shown in FIG. The hydraulic circuit {differential pressure take-out valve 37 (FIG. 13), hydraulic piping, etc.} for this purpose can be omitted. When such a configuration is adopted, the pressure adjusting valve 29, the controller 16, and the line pressure control electromagnetic switching valve 18 are added to the hydraulic pressure adjusting means described in the claims. Equivalent to.

  In any case, when the configuration as described above is adopted, the controller 16 detects the differential pressure (passing torque) detected by the hydraulic sensors 39a and 39b and the transmission ratio of the toroidal continuously variable transmission 4. If necessary, a target value of the hydraulic pressure to be introduced into the hydraulic chamber of the pressing device 14 is set (calculated) according to other state quantities such as the oil temperature circulating in the toroidal continuously variable transmission 4. ) In this case, the speed ratio is determined by, for example, the input side and output side rotational speed sensors 40 and 41 for detecting the rotational speeds of the input side and output side disks 10 and 11 (the rotational speeds of both disks 10 and 11). As a ratio). The oil temperature can be detected by, for example, an oil temperature sensor 42 provided in the casing of the toroidal continuously variable transmission 4. Further, the target value is obtained in advance by experiment or calculation as a correlation between the value such as the differential pressure (passing torque), the gear ratio, the oil temperature, and the target value corresponding to these values, for example. The memory of the controller 16 is stored as a map (MAP) or a calculation formula. Such a controller 16 sets (calculates and obtains) the target value corresponding to the differential pressure (passing torque), gear ratio, oil temperature, etc. at that time using these maps and calculation formulas. In addition, the opening / closing of the line pressure control electromagnetic on-off valve 18 is adjusted (duty ratio control) to adjust to the target value. Then, based on the opening / closing adjustment, the opening pressure of the pressing force adjusting valve 29, and hence the hydraulic pressure introduced into the hydraulic chamber of the pressing device 14 is adjusted to the target value, and the pressing force generated by the pressing device 14 is adjusted. Are properly regulated.

  By the way, even if the differential pressure is detected by the hydraulic sensors 39a and 39b as described above, the hydraulic pressure corresponding to the differential pressure as shown in FIGS. The pressure oil in the primary line 50 adjusted by the pressing force adjusting valve 29 is supplied to the manual hydraulic pressure switching valve 31 and the pressure reducing valve in addition to the pressing device 14 even if the structure is introduced directly to the pressing force adjusting valve 29. 38, the low speed clutch and the high speed clutch 7 and 8 are also introduced through the low speed clutch and high speed clutch switching valves 25 and 26, respectively. In other words, the pressure oil in the primary line 50 adjusted by the pressure adjusting valve 29 is reduced to a predetermined pressure (for example, 1.4 [MPa] in the hydraulic circuit of FIG. 13) by the pressure reducing valve 38, and the low speed The low-speed and high-speed clutches 7 and 8 are connected by introducing them into the high-speed and high-speed clutches 7 and 8. In the case of such a structure, by using a common hydraulic source for the pressing device 14 and the clutch device 6 (low-speed and high-speed clutches 7 and 8), the hydraulic system is simplified, downsized, and the amount of oil is reduced. High efficiency and cost reduction can be achieved. However, such a structure may cause the following problems.

  First, FIG. 9, which will be described in detail later, corresponds to an example of a continuously variable transmission according to an embodiment described later, the speed ratio of the entire continuously variable transmission, and the pressing device 14 at the maximum torque. The required loading pressure corresponding to the hydraulic pressure to be introduced into the hydraulic chamber 51 (see FIGS. 2, 3, and 13), and the hydraulic chambers 52a and 52b of the low-speed and high-speed clutches 7 and 8 (see FIGS. 2, 3, and 13). ) Shows an example of the relationship with the required clutch pressure corresponding to the hydraulic pressure to be introduced. The required loading pressure corresponds to a hydraulic pressure corresponding to the pressing force to be generated by the pressing device 14. The required clutch pressure is a hydraulic pressure corresponding to the fastening pressure to be generated in each of the low speed and high speed clutches 7 and 8 (power is transmitted without causing slippage in the low speed and high speed clutches 7 and 8. Corresponding to the required hydraulic pressure). Of these, the required clutch pressure can be obtained from the following equation (1) as described in Non-Patent Document 1, for example.

この式（１）中、Ｔc はクラッチ装置の伝達トルク［Ｎｍ］に、ｎはクラッチ摩擦面（クラッチ板）の数に、μは摩擦係数に、Ｐc は作動油圧［Ｐａ］に、Ｄpoはクラッチ装置を構成するピストンの外径［ｍ］に、Ｄpiは同じくピストンの内径［ｍ］に、Ｆr はピストンのリターンスプリングのセット荷重［Ｎ］に、Ｄo はクラッチ摩擦面（クラッチ板）の外径［ｍ］に、Ｄi はクラッチ摩擦面（クラッチ板）の内径［ｍ］に、それぞれ対応する。この様な式（１）の伝達トルクＴc ［Ｎｍ］と作動油圧Ｐc ［Ｐａ］との関係から、最大トルク時の伝達トルク［Ｎｍ］に対応する作動油圧［Ｐａ］として、上記必要クラッチ圧を求める事ができる。

In this equation (1), Tc is the transmission torque [Nm] of the clutch device, n is the number of clutch friction surfaces (clutch plates), μ is the friction coefficient, Pc is the hydraulic pressure [Pa], and Dpo is the clutch The piston outer diameter [m], Dpi is also the piston inner diameter [m], Fr is the piston return spring set load [N], and Do is the clutch friction surface (clutch plate) outer diameter. Di corresponds to the inner diameter [m] of the clutch friction surface (clutch plate). From the relationship between the transmission torque Tc [Nm] and the hydraulic pressure Pc [Pa] in the equation (1), the required clutch pressure is set as the hydraulic pressure [Pa] corresponding to the transmission torque [Nm] at the maximum torque. You can ask for it.

  In the case of the structure having the relationship between the required loading pressure and the required clutch pressure as shown in FIG. 9 as described above, the maximum value of the required clutch pressure is about 1.6 [MPa] (point a in FIG. 9). In the case of such a structure, if the pressure reducing valve 38 is set to 1.6 [MPa], the hydraulic pressure of the primary line 50 adjusted to the required loading pressure becomes the maximum value of the required clutch pressure (1.6 [MPa]. ], It is possible to prevent excessive high hydraulic pressure from being introduced into the low speed and high speed clutches 7 and 8 (because of excessive fastening pressure), thereby ensuring durability and downsizing the device. Etc. On the other hand, when the required loading pressure is smaller than 1.6 [MPa], the hydraulic pressure of the primary line 50 adjusted to a value smaller than 1.6 [MPa] It is introduced into the clutches 7 and 8. Depending on the relationship between the required loading pressure and the required clutch pressure, for example, the required loading pressure is smaller than the required clutch pressure in the range of the speed ratio indicated by K in FIG. In such a case, when the hydraulic pressure of the primary line 50 adjusted to the required loading pressure is introduced as it is to the low speed and high speed clutches 7 and 8, the hydraulic chambers 52a and 52b of the clutches 7 and 8 are used as they are. Insufficient oil pressure (necessary clutch pressure) is not introduced, and there is a possibility that slip (clutch plate slip) may occur at the engagement portions of the clutches 7 and 8.

  Further, in any of the above-described structures (either a structure in which the differential pressure is detected by the hydraulic pressure sensors 39a and 39b or a structure in which the hydraulic pressure corresponding to the differential pressure is directly introduced into the pressure adjusting valve 29) Adjustment of the hydraulic pressure (hydraulic pressure of the primary line 50) introduced into the device 14 (and hence the low-speed and high-speed clutches 7 and 8 to be connected) passes through the toroidal continuously variable transmission at that time. This is based on the differential pressure corresponding to the torque (passing torque). However, in the case of adopting the technique of connecting both the low-speed and high-speed clutches 7 and 8 at the time of mode switching as described above with such a structure, as it is, immediately after the completion of the mode switching (the moment when the mode switching is completed). ) May not be able to generate an appropriate pressing force from the pressing device 14. At the same time, during or immediately after the mode switching, there is a possibility that slip (clutch plate slip) may occur at the engaging portions of the low speed and high speed clutches 7 and 8.

  That is, when both the low speed and high speed clutches 7 and 8 are connected at the same time, the torque passing through the toroidal continuously variable transmission 4 (passing torque), and thus the difference corresponding to the passing torque. The pressure does not correspond to the force (power, torque) output from the engine 1 at that time (becomes irrelevant). In this manner, when both the clutches 7 and 8 are connected at the same time, the passing torque, and thus the differential pressure, is a slight variation in the gear ratio of the toroidal continuously variable transmission 4 at that time. Will change accordingly. For example, the speed ratio of the toroidal continuously variable transmission 4 is equal to the mode switching point {the speed ratio of the continuously variable transmission is the same regardless of whether the low speed clutch 7 or the high speed clutch 8 is connected. 15, for example, both the low speed and the high speed clutches 7 and 8 are simultaneously in a state where the speed ratio corresponding to the point (b) in FIG. When connected, the torque (passing torque) passing through the toroidal-type continuously variable transmission 4 becomes zero, and the differential pressure becomes zero.

  That is, the force (power, torque) output from the engine 1 is transmitted to the planetary gear type transmission 5 without passing through the toroidal type continuously variable transmission 4 (the torque passes through the toroidal type continuously variable transmission 4). The passing torque, and thus the differential pressure is also zero. In this case, regardless of the magnitude (power or torque) output from the engine 1 (either large or small), the passing torque and thus the differential pressure becomes zero. . On the other hand, when the low speed and high speed clutches 7 and 8 are simultaneously connected in a state slightly deviated from the mode switching point, the transmission ratio of the toroidal type continuously variable transmission 4 becomes the mode switching point. Is forcibly shifted (torque shift). Then, based on the force that is shifted to the mode switching point in this way, the differential pressure increases, for example, depending on the torque shift amount at that time, the direction of torque shift (acceleration, deceleration), or the like. Or get smaller. That is, in this case, regardless of the force (power, torque) output from the engine 1, the passing torque and thus the differential pressure change.

  In any case, as described above, with the low-speed and high-speed clutches 7 and 8 being simultaneously connected, the above differential pressure becomes the torque (passing torque) that passes through the toroidal continuously variable transmission at that time. Even if it corresponds, it does not correspond to the torque output from the engine 1. For this reason, the pressing force generated by the pressing device 14 (the target value of the hydraulic pressure introduced into the pressing device 14) is directly based on the differential pressure in a state where both the clutches 7 and 8 are simultaneously connected as described above. The pressure (or the target value) immediately after mode switching is completed (immediately after the other clutch that was connected is disconnected) is continuously adjusted (or the target value is set based on the differential pressure). ) May deviate from the values (necessary values, required loading pressure) required in the travel mode after the mode switching is completed. That is, the pressing force (or target value) is output from the engine 1 immediately after the mode switching is completed (the moment when the other clutch is disconnected from the state where both clutches are connected simultaneously), and the toroidal It is possible to deviate from an appropriate value (necessary value, necessary loading pressure) corresponding to the magnitude of torque (passing torque) that is input to the continuously variable transmission 4 and passes through the toroidal continuously variable transmission 4. There is sex.

  When such a deviation is large, immediately after the mode switching is completed (the moment when the mode switching is completed), the pressing force generated by the pressing device 14 (hydraulic pressure introduced into the pressing device 14) becomes excessive. Or may be too small. For example, immediately after the mode switching is completed, when the hydraulic pressure introduced into the pressing device 14 and, further, the pressing force generated by the pressing device 14 becomes excessive, the input-side and output-side discs 10, The pressing force of the traction portion (rolling contact portion) between the side surface 11 and the peripheral surface of each power roller 12 becomes excessively large (over-pressing), which may lead to a decrease in transmission efficiency and a decrease in durability. On the other hand, when the hydraulic pressure introduced into the pressing device 14, and thus the pressing force, becomes too small, the pressing force of the traction portion (rolling contact portion) is insufficient. May cause harmful slip called gloss slip at the traction portion (rolling contact portion), leading to a decrease in transmission efficiency and a decrease in durability. In addition, when the hydraulic pressure introduced into the pressing device 14 becomes too small in this way, the hydraulic pressure introduced into the low speed and high speed clutches 7 and 8 may be lowered (insufficient) more than necessary. is there. In this case, there is a possibility that slipping (clutch plate slipping) may occur at the engaging portions of the low speed and high speed clutches 7 and 8 during or immediately after mode switching.

  As described above, the pressing force deviates from the required value (necessary loading pressure) immediately after the mode switching is completed (or easily deviates), and slips at the engaging portions of the low speed and high speed clutches 7 and 8 (the clutch plate In addition to the cause that the differential pressure does not correspond to the torque output from the engine 1 during the mode switching as described above, the toroidal type occurs before and after the mode switching. One example is that the direction of torque (passing torque) passing through the continuously variable transmission 4 changes (reverses). That is, when the passing torque changes (inverted), in other words, when the passing torque changes from the positive direction to the negative direction or from the negative direction to the positive direction, the mode is being switched. However, the passing torque becomes zero although it is a short time. As the passing torque becomes zero, the differential pressure corresponding to the passing torque also becomes zero. The target value set based on the differential pressure, and further, the pressing device 14 and the low speed are set. Also, the hydraulic pressure introduced into each of the high speed clutches 7 and 8 is excessively small {for example, the smallest value (for example, 0)}.

  When the hydraulic pressure introduced into the target device during the mode switching and thus the pressing device 14 and the low speed and high speed clutches 7 and 8 becomes excessively small in this way, the low speed and high speed are switched during the mode switching. There is a possibility that slipping (slipping of the clutch plate) may occur at the fastening portion of each of the clutches 7 and 8. In addition, it takes time until the pressing force generated by the pressing device 14 reaches a value (necessary value, required loading pressure) required immediately after the mode switching is completed immediately after the mode switching is completed. Accordingly, the pressing force immediately after the completion of the mode switching is likely to deviate from the necessary value (necessary loading pressure) (is likely to be insufficient). In addition, the hydraulic pressure introduced into the pressing device 14 and the low-speed and high-speed clutches 7 and 8 in this way is excessively small. This fluctuation of the hydraulic pressure (the pressing force of the pressing device 14, low-speed and high-speed This may lead to a change in the gear ratio (torque shift) accompanying a change in the engagement pressure of the clutches 7 and 8, which is not preferable from the viewpoint of preventing such a torque shift.

Japanese Patent Laid-Open No. 10-196759 JP-A-11-108147 JP 2004-225888 A JP 2004-211836 A JP 2004-76940 A Japanese Patent Laid-Open No. 9-210191 Yoshio Morimoto, “Introduction to CVT”, Grand Prix Publishing Co., Ltd., October 2004, P93-P95

  In view of the circumstances as described above, the continuously variable transmission according to the present invention has a structure in which the clutch device is connected by introducing the pressure oil introduced into the pressing device into the clutch device, thereby transmitting traction. The present invention has been invented to realize a structure capable of securing the fastening pressure of the clutch device to be connected while securing an appropriate pressing force at the portion (rolling contact portion).

The continuously variable transmission of the present invention includes a toroidal continuously variable transmission and a clutch device.
Among these, the toroidal continuously variable transmission includes first and second disks (for example, input side and output side disks), a plurality of power rollers, a plurality of support members (for example, trunnions), an actuator, A pressing device.
Of these, the first and second disks are arranged concentrically and rotatably relative to each other.
Each of the power rollers is sandwiched between the inner surfaces of the first and second disks facing each other, and transmits power (force, torque) between the first and second disks. To do.
The support members rotatably support the power rollers.
The actuator displaces the support members in the axial directions of the pivots provided at both ends thereof to change the gear ratio between the first disk and the second disk.

The pressing device is a hydraulic device that generates a pressing force proportional to the hydraulic pressure with the introduction of the hydraulic pressure, and presses the first disk and the second disk toward each other. is there.
The hydraulic pressure adjusting means for adjusting the hydraulic pressure to be introduced into the pressing device sets (calculates) the hydraulic pressure to be introduced into the hydraulic chamber of the pressing device in accordance with the state quantity representing the operation status at that time. The target value corresponding to the pressing force to be generated by the pressing device is adjusted.
The clutch device is connected based on the introduction of the hydraulic pressure adjusted to the target value by the hydraulic pressure adjusting means.

  Note that the state quantities representing the driving conditions include, for example, “force passing through a toroidal type continuously variable transmission (passing torque)”, “drive source connected to the toroidal type continuously variable transmission (eg, engine, electric motor, etc.) ) Output power (output torque, engine torque) "," transmission ratio of toroidal type continuously variable transmission (speed ratio between first disk and second disk) "," toroidal type continuously variable transmission Oil temperature of lubricating oil (traction oil) circulating in the machine ”. Of these, the “passing torque” is, for example, the hydraulic pressure between a pair of hydraulic chambers 36 a and 36 b (see FIG. 13) constituting the actuator 13 as described in the section “Background Art”. This corresponds to the force (power, torque) obtained based on the difference (differential pressure). The “output torque” includes, for example, an accelerator operation amount (accelerator opening degree, accelerator pedal depression amount) and a rotational speed (engine rotational speed) of a drive source (engine, electric motor, etc.) as described later. That is, it corresponds to the force (power, torque, output torque, engine torque) output from this drive source (or predicted to be output).

  In any case, it is preferable to use at least “passing torque” or “output torque” for setting (calculating) the target value. The “at least” means not only the “passing torque” or “output torque” but also the “shift” in addition to the “passing torque” or “output torque” when setting (calculating) the target value. This means that the use of other state quantities such as “ratio” and “oil temperature” together with “passing torque” or “output torque” is not excluded. Further, it is preferable that these “passing torque” and “output torque” are properly used as necessary (the one having the largest target value is used) as will be described later. In any case, not only the “passing torque” or “output torque” but also the “passing torque” or “output torque” and the “transmission ratio” (if necessary, “oil It is more preferable to carry out based on “temperature”.

In particular, in the continuously variable transmission of the present invention, the hydraulic pressure adjusting means is necessary for connection of the target value corresponding to the hydraulic pressure to be introduced into the pressing device at that time, and the clutch device. The clutch target value corresponding to the hydraulic pressure to be introduced into this clutch device is compared, and the larger value is set as the actual target value (actual target value), and the hydraulic pressure is adjusted to this target value (actual target value). To do.
For this purpose, for example, as in the invention described in claim 2, the actuator that changes the speed ratio between the first disk and the second disk is hydraulic.
Further, the hydraulic pressure adjusting means has first and second functions for obtaining (calculating) a target value corresponding to the hydraulic pressure to be introduced into the pressing device, and a clutch corresponding to the hydraulic pressure to be introduced into the clutch device. It is assumed that the third and fourth functions for obtaining the target value are provided.

Of these, the first function is to obtain (calculate) a (first) target value based on at least the “force passing through the toroidal type continuously variable transmission (passing torque)”. That is, the (first) target value is obtained (calculated) based on the difference in hydraulic pressure (differential pressure) between a pair of hydraulic chambers provided in the actuator corresponding to this “passing torque”.
The second function is based on “a force (output torque, engine torque) output from a drive source (engine, electric motor, etc.) connected to the toroidal type continuously variable transmission” (second). A target value is obtained (calculated). That is, the amount of operation of the accelerator device for adjusting the output of at least the drive source connected to the toroidal continuously variable transmission corresponding to this “output force” (accelerator opening, accelerator pedal depression amount) And the (second) target value is obtained (calculated) based on the rotational speed of the drive shaft of the drive source (engine rotational speed).

The third function is based on a difference in hydraulic pressure (differential pressure) between the hydraulic chambers of the actuator corresponding to at least the “passing force”. Is obtained (calculated).
In addition, the fourth function includes the operation amount of the accelerator device (accelerator opening degree, depression amount of the accelerator pedal) and the rotational speed of the drive shaft of the drive source (engine) corresponding to at least the “output force”. (Second) clutch target value is obtained (calculated) based on (rotational speed).
A first target value obtained (calculated) based on the first function; a second target value obtained (calculated) based on the second function; The first clutch target value obtained (calculated) based on the function is compared with the second clutch target value obtained (calculated) based on the fourth function, and the largest of these is compared. The value is set as an actual target value (actual target value), and the hydraulic pressure is adjusted to this target value (actual target value).

In short, the hydraulic pressure adjusting means adds the first value corresponding to the hydraulic pressure to be introduced to the pressing device based on the differential pressure at that time (calculates), and the accelerator device at that time. The second function is obtained (calculated) based on the operation amount (accelerator opening, accelerator pedal depression amount) and the rotational speed of the drive source (engine rotational speed). At the same time, the hydraulic pressure adjusting means corresponds not only to the function (first and second functions) for obtaining the target value corresponding to the hydraulic pressure to be introduced into the pressing device, but also to the hydraulic pressure to be introduced into the clutch device. There is also a function (third and fourth functions) for obtaining a clutch target value. As for the function for obtaining the clutch target value, the third function to be obtained (calculated) based on the differential pressure at that time, and the operation amount of the accelerator device at that time (accelerator opening, depression of the accelerator pedal) A fourth function obtained (calculated) based on the amount) and the rotational speed of the drive source (engine rotational speed).
The largest value among the first and second target values and the first and second clutch target values obtained (calculated) by the first to fourth functions is set to the actual target value (actual target value). Value) and adjust the oil pressure to this target value (actual target value).

In the case of implementing the continuously variable transmission of the present invention as described above, preferably a toroidal continuously variable transmission and a differential unit (for example, a gear-type differential unit) as in the invention described in claim 3. And a planetary gear type transmission) are combined through a clutch device.
Of these, the clutch device includes a first clutch (for example, a low speed clutch) and a second clutch (for example, a high speed clutch).
Of these, the first clutch (low speed clutch) is connected when realizing the first mode (for example, the low speed mode) for increasing the reduction ratio, and the second mode (for example, the high speed mode) for reducing the same. It is assumed that the connection is broken when realizing the above.
The second clutch (high speed clutch) is connected when realizing the second mode (high speed mode) and disconnected when realizing the first mode (low speed mode). Shall.

Further, when the invention of the continuously variable transmission described in claim 3 is carried out, the actuator is preferably provided as in the invention described in claim 4 as in the invention described in claim 4. Is hydraulic, and the hydraulic pressure adjusting means has first to fourth functions.
Then, during operation in the first mode (low speed mode) or the second mode (high speed mode), the first target value obtained (calculated) based on the first function and the first mode A second target value obtained (calculated) based on the second function, a first clutch target value obtained (calculated) based on the third function, and the fourth function The second clutch target value obtained (calculated) is compared, the largest value is set as the actual target value (actual target value), and the hydraulic pressure is set to this target value (actual target value). Adjust.

Further, when the invention of the continuously variable transmission according to claims 3 to 4 as described above is carried out, the clutch device is preferably connected to the first mode (as in the invention according to claim 5). One of the first clutch (low speed clutch) and the second clutch (high speed clutch) at the time of mode switching between the low speed mode) and the second mode (high speed mode). Assume that after connecting a clutch that has not been connected until then, by disconnecting the clutch that was previously connected by the other clutch, the time for which both clutches are simultaneously connected is set.
The hydraulic pressure adjusting means has at least the second function and the fourth function. That is, based on at least the operation amount of the accelerator device (accelerator opening, accelerator pedal depression amount) and the rotation speed of the drive shaft of the drive source (engine rotation speed), the hydraulic pressure to be introduced into the pressing device is determined. Similarly to the second function for obtaining (calculating) the corresponding (second) target value, the fourth function for obtaining (calculating) the (second) clutch target value corresponding to the hydraulic pressure to be introduced into the clutch device. It shall be provided with the function.
At the time of mode switching between the first mode (low speed mode) and the second mode (high speed mode) (during mode switching), for example, the mode switch has not been performed until then. From the start of the clutch connection until the other clutch connected until it is disconnected (until it starts to disconnect) (at least while both the first and second clutches are connected simultaneously) A target value (second target value) obtained (calculated) based on the second function and a clutch target value (second clutch target value) obtained (calculated) based on the fourth function ), A larger target value is set as an actual target value (actual target value), and the hydraulic pressure is adjusted to this target value (actual target value).

  In this case, as described in claim 6, when the mode is switched between the first mode (low speed mode) and the second mode (high speed mode) (at least both the first and second clutches are (While connected simultaneously), based on the second function, the (second) target value corresponding to the current driving mode and the (second) target value corresponding to the driving mode to be realized next And (second) clutch target value corresponding to the next driving mode to be realized and the (second) clutch target value corresponding to the current driving mode based on the fourth function. Each value is calculated (calculated), and the four calculated (calculated) values are compared, and the target value of the largest value is set as the actual target value (actual target value). Adjust the hydraulic pressure to the value (actual target value).

According to the continuously variable transmission of the present invention configured as described above, the hydraulic pressure introduced into the pressing device is introduced into the clutch device, so that the clutch device is connected and the traction portion (rolling force) that transmits power is provided. The engagement pressure of the clutch device to be connected can be secured while securing an appropriate pressing force at the contact portion).
That is, the hydraulic pressure adjustment means at that time has a target value corresponding to the hydraulic pressure to be introduced into the pressing device, and a clutch target value corresponding to the hydraulic pressure to be introduced into the clutch device necessary for connection of the clutch device. Are set as an actual target value (actual target value), and the hydraulic pressure is adjusted to the target value (actual target value). For this reason, even when the required loading pressure is smaller than the required clutch pressure, sufficient hydraulic pressure (necessary clutch pressure) can be introduced into the hydraulic chamber of the clutch device, and slipping (clutch plate slipping) occurs at the engaging portion of the clutch device. Can be prevented.

  In the second and fourth aspects of the invention, the first target value and the first clutch target are determined based on the hydraulic pressure difference (differential pressure) between the pair of hydraulic chambers provided in the actuator. In addition to obtaining (calculating) a value, the amount of operation of the accelerator device (accelerator opening, accelerator pedal depression amount) for adjusting the output of the drive source and the rotation speed of the drive shaft of the drive source (engine rotation speed) ) To obtain (calculate) a second target value and a second clutch target value. Then, the largest value among the first and second target values and the first and second clutch target values obtained (calculated) in this way is set as the actual target value, and the hydraulic pressure is set to the actual target value. Adjust. Therefore, regardless of the driving situation, that is, for example, when there is a sudden fluctuation in power, such as during a sudden acceleration that tends to cause a delay in hydraulic response (a change in differential pressure is likely to appear later) Even during normal operation, the actual target value can always be large (can be prevented from becoming too small), and the clutch device to be connected while ensuring an appropriate pressing force at the traction portion (rolling contact portion). The fastening pressure can be secured.

  In the case of the invention described in claim 5, the target value and the clutch target value are not obtained (calculated) based on the differential pressure during mode switching. That is, during the mode switching, it is obtained (calculated) based on the operation amount of the accelerator device (accelerator opening degree, accelerator pedal depression amount) and the rotational speed of the drive source (engine rotational speed). For this reason, even during mode switching (even when both the first and second clutches are simultaneously connected), the pressing force generated by the pressing device and the engagement pressure of the clutch device are controlled by the driving at that time. It can be adjusted to an appropriate value corresponding to the force (power, torque) output from the source. In addition, when the mode is switched, there is also a decrease (insufficiency) in the pressing force and fastening pressure due to the reverse direction of the torque (passing torque) passing through the toroidal type continuously variable transmission (the differential pressure becomes zero). Can be prevented. For this reason, in addition to being able to adjust the pressing force and the fastening pressure to appropriate values, unnecessary fluctuations in the pressing force and the fastening pressure can be reduced (the pressing force and the fastening pressure are not greatly changed), It is also possible to reduce the torque shift associated with fluctuations in the pressing force and the fastening pressure.

  Further, in the case of the invention described in claim 6, during the mode switching, the target value and the clutch target value corresponding to the current driving mode and the driving mode to be realized next are obtained, and the largest of these is obtained. The target value is set as the actual target value (actual target value), and the hydraulic pressure is adjusted to this target value. For this reason, even if the required loading pressure and the required clutch pressure are different before and after the mode switching, it is possible to reliably prevent the pressing force and the fastening pressure from being insufficient from the start to the completion of the mode switching.

  1 to 11 show an example of an embodiment of the present invention. The feature of this example is that the engagement pressure of the clutch device 6 (low speed and high speed clutches 7 and 8) to be connected while applying an appropriate pressing force at the traction part (rolling contact part) for transmitting power. In order to ensure this, the structure of the pressure device 14 and the portion for adjusting the hydraulic pressure introduced into the clutch device 6 (hydraulic adjusting means) and the procedure for adjusting the hydraulic pressure are devised. Since the structure and operation of the other parts are the same as those of the conventional structure shown in FIGS. 12 to 13 described above, the overlapping description will be omitted or simplified, and the following description will focus on the characteristic parts of this example. In the case of this example, the relationship between the speed ratio (speed increase ratio) of the continuously variable transmission as a whole and the speed ratio (speed increase ratio) of the toroidal continuously variable transmission 4 is shown in FIG. 15, for example. It is set like this. Such a setting can be performed, for example, by regulating the reduction ratio of the planetary gear type transmission 5 or the like, the gear ratio of the transmission gear, and the like.

  The configurations of the hydraulic circuits shown in FIGS. 2 and 3 of this example are different from each other in that a differential pressure take-out valve 37 (see FIG. 3) is provided. That is, in the case of the hydraulic circuit of FIG. 3, a differential pressure take-off valve 37 similar to that of the hydraulic circuit shown in FIG. 13 is provided, whereas in the case of the hydraulic circuit of FIG. Such a differential pressure extraction valve 37 is not provided (omitted). However, in the case of the hydraulic circuit in FIG. 3, the pilot chamber 43 of the differential pressure take-out valve 37 communicates with the oil reservoir 28, and an oil passage 44 a between the differential pressure take-out valve 37 and the pressing force adjustment valve 29, The differential pressure take-out valve 37 is prevented from functioning (for example, the hydraulic pressure corresponding to the differential pressure is not introduced into the pressing force adjusting valve 29), for example, by closing 44b with a blind plug. That is, the hydraulic circuit in FIG. 3 is substantially the same as the hydraulic circuit in FIG. 2 in which the differential pressure take-out valve 37 is omitted. Therefore, the following description will be made without distinguishing the structure of FIG. 2 from the structure of FIG. 3 (the following description corresponds to the structure of both FIG. 2 and FIG. 3).

  In the case of the conventional structure shown in FIGS. 12 to 13, the switching state of the low speed and high speed clutches 7 and 8 (switching between the low speed mode and the high speed mode) is changed to one shift electromagnetic. In contrast to the valve 20 (FIGS. 12 to 13), in the case of this example, the low-speed clutch and high-speed clutch solenoid valves 45 and 46 (two solenoid valves 45 and 46) are used. In the case of this example, mode switching between the low speed mode and the high speed mode is performed as follows. That is, when switching from the low speed mode to the high speed mode while traveling in the low speed mode (only the low speed clutch 7 is connected), as shown in FIG. A command (control signal) to connect the high speed clutch 8 is issued from the controller 16 to the high speed clutch electromagnetic valve 46 in order to connect (ON) the high speed clutch 8 that was not present (high speed clutch electromagnetic valve). 46 is turned on). Thereafter, in order to disconnect (turn off) the low-speed clutch 7 that has been connected so far, the controller 16 instructs the low-speed clutch solenoid valve 45 to disconnect the low-speed clutch 7 ( Control signal) (the low-speed clutch solenoid valve 45 is energized).

  On the other hand, when the mode is switched from the high speed mode to the low speed mode while traveling in the high speed mode (only the high speed clutch 8 is connected), as shown in FIG. In order to connect (ON) the low-speed clutch 8 that was not present, a command (control signal) to connect the low-speed clutch 7 is issued from the controller 16 to the low-speed clutch solenoid valve 45 (low-speed clutch electromagnetic). The valve 45 is deenergized). Thereafter, in order to disconnect (turn off) the high-speed clutch 8 that has been connected so far, the controller 16 instructs the high-speed clutch solenoid valve 46 to disconnect the high-speed clutch 8 ( Control signal) (the high speed clutch switching valve 46 is deenergized).

  In the case of this example, the electromagnetic valve 19 for correcting the gear ratio of the toroidal-type continuously variable transmission 4 as in the conventional structure shown in FIGS. The correction control valves 24a and 24b and the forward / reverse switching valve 47 (see FIG. 13) are not provided (omitted). Further, in the case of the present example, a pair of actuators 13 constituting the pressing force adjusting valve 29 for adjusting the hydraulic pressure introduced into the pressing device 14 as in the conventional structure shown in FIGS. A configuration that directly introduces the hydraulic pressure difference (differential pressure) between the hydraulic chambers 36a and 36b is not adopted. That is, in the case of this example, the differential pressure is detected by a pair of hydraulic sensors 39a and 39b (39 in FIG. 1) provided in the hydraulic chambers 36a and 36b, and based on the detected differential pressure, The pressing force generated by the pressing device 14 is adjusted.

  For this reason, in the case of this example, the pressure oil adjusted to a predetermined pressure based on the opening / closing of the line pressure control electromagnetic opening / closing valve 18 controlled by a command from the controller 16 is changed to the second pressure of the pressing force adjusting valve 29. The pilot section 33 is introduced. At the same time, the controller 16 obtains (estimates or calculates) the magnitude of the torque (passing torque) that passes through the toroidal continuously variable transmission 4 and is calculated from the differential pressure. A function (first function) for setting (calculating) a target value corresponding to the pressing force to be generated by the pressing device 14 based on the speed ratio of the step transmission 4 is provided. The speed ratio of the toroidal-type continuously variable transmission 4 can be detected by the rotational speed sensors 40 and 41 on the input side and output side (as the ratio of the rotational speeds of the disks 10 and 11 on the input side and output side), It can also be obtained by measuring the inclination angle (rotation angle about the pivot axis) of the support member (trunnion) that supports each power roller 12.

  Further, the target value of the hydraulic pressure is obtained in advance through experiments and calculations as a correlation between the target value, the differential pressure (passing torque), and the transmission gear ratio, and a map or the like is stored in the memory of the controller 16. It is memorized as a calculation formula and a diagram. It should be noted that such maps, calculation formulas, and diagrams are common to the low-speed mode and the high-speed mode (for example, a common calculation formula), or correspond to the low-speed mode (for example, the low-speed mode MAP or diagram). ) And those corresponding to the high-speed mode (for example, a high-speed mode MAP and a diagram) can be used separately. In any case, the controller 16 corresponds to the differential pressure (passing torque) and the gear ratio (tilt angle) at that time based on such a map, calculation formula, diagram, or the like. A target value is set and the opening / closing of the line pressure control electromagnetic on-off valve 18 is adjusted (duty ratio control) in order to adjust to the target value. Then, based on this opening / closing adjustment, the opening pressure of the pressing force adjusting valve 29, and hence the hydraulic pressure introduced into the hydraulic chamber of the pressing device 14 is adjusted to the target value, and the pressing force generated by the pressing device 14 is adjusted. Are properly regulated.

  However, simply setting the target value based only on the differential pressure in this way may cause the pressing force generated by the pressing device 14 to become excessive or too small at the time of mode switching. . In addition, even when the mode is not switched (low speed mode or high speed mode), the sensor for detecting the differential pressure, the switching valve, etc., when the power suddenly fluctuates during sudden acceleration (when the accelerator pedal is depressed suddenly) With the response delay, the pressing force generated by the pressing device 14 may be insufficient. Therefore, in the case of this example, the target value is determined based on the operation amount of the accelerator device (accelerator opening, accelerator) for adjusting the output of the engine 1 connected to the toroidal type continuously variable transmission 4 in addition to the differential pressure. The amount of depression of the accelerator pedal) and the rotational speed (engine rotational speed) of the drive shaft (crankshaft) of the engine 1 are obtained.

  That is, the controller 16 constituting the hydraulic pressure adjusting means of this example determines the magnitude of the force transmitted between the input side and output side disks 10 and 11 necessary for setting the target value. In addition to the function (first function) obtained based on the differential pressure, the function obtained based on the operation amount (accelerator opening) of the accelerator device and the rotational speed of the drive shaft of the engine 1 (engine rotational speed). (Second function) is also provided. Then, the target value is set based on the second function as required (for example, when the power changes suddenly during mode switching or sudden acceleration). The operation speed and operation amount of the accelerator device can be detected by an accelerator sensor 48 for detecting the operation amount of the accelerator pedal (stepping amount, stepping amount, and opening amount). The rotational speed of the engine 1 can be detected by a rotational speed sensor (or tachometer signal) (not shown) for detecting the rotational speed of the drive shaft (crankshaft) of the engine 1 (input side rotational speed sensor). 40 can also be used).

In any case, the controller 16 is output from the engine 1 based on the operation amount of the accelerator device (accelerator opening) and the rotational speed of the drive shaft of the engine 1 (engine rotational speed) (or through). Is capable of calculating (estimating) the magnitude of force (output torque, engine torque) that is predicted to be output. For this purpose, the memory of the controller 16 stores the characteristics of the engine 1 mounted on the vehicle, for example, the characteristics of the engine torque [Nm] corresponding to the accelerator opening [%] and the engine speed [min ⁻¹ ]. For example, it is stored (programmed) as a map, a calculation formula, or a diagram. Then, the controller 16 calculates (estimates) the engine torque corresponding to the accelerator opening and the engine speed at that time based on the engine characteristics as described above. In addition, when communication is possible between the engine controller 49 for controlling the engine 1 and the controller 16 using, for example, a CAN (Controller Area Network) or the like, the engine controller 49 sets the accelerator opening. Corresponding engine torque data can also be obtained. However, in addition to the possibility of causing a time delay during communication, such a means cannot be adopted in the case of a vehicle that cannot communicate (or has no communication means). For this reason, it is preferable to calculate (estimate) the engine torque from the accelerator opening and the engine rotational speed as described above using a map, a calculation formula, a diagram, or the like.

  When the output torque (engine torque) is obtained as described above, the controller 16 uses the controller 16 based on the output torque (engine torque) and the gear ratio of the toroidal type continuously variable transmission 4. 14 sets (calculates) a target value corresponding to the pressing force to be generated. Even when the target value is set based on the output torque (engine torque) and the gear ratio in this way, the correlation between the target value, the output torque (engine torque) and the gear ratio is controlled by the control. It is stored in the memory of the device 16 as a MAP, a calculation formula, and a diagram, and is set (calculated) using such a MAP, a calculation formula, a diagram, and the like. It should be noted that such maps, calculation formulas, line diagrams, and the like are common to the low-speed mode and the high-speed mode (for example, a common calculation formula), or correspond to the low-speed mode (for example, a low-speed mode MAP or line It is also possible to use different ones for the high-speed mode (for example, MAP and diagram for high-speed mode).

  Further, for example, the engine torque (output torque) used in the MAP, calculation formula, diagram, etc. may be calculated (created) in correspondence with the torque (input torque) input to the toroidal type continuously variable transmission 4. preferable. In this case, in order to calculate the torque input to the toroidal-type continuously variable transmission 4 from the engine torque, a member (torque passes) provided between the engine 1 and the toroidal-type continuously variable transmission 4. The efficiency of the gears to be This efficiency varies depending on the gear ratio of the toroidal-type continuously variable transmission 4 and the travel mode (low speed mode / high speed mode), so it is difficult to calculate strictly. For this reason, the MAP and diagram as described above are obtained, for example, by experiments (created using experimental values). If the efficiency between the engine 1 and the toroidal-type continuously variable transmission 4 can be obtained, a calculation formula using this efficiency is used instead of the MAP or diagram as described above. You can also do it.

  If the target value corresponding to the output torque (engine torque) and the gear ratio at that time is set using the diagram, calculation formula, MAP, or the like as described above, the controller 16 In order to adjust to the target value, the opening / closing of the line pressure control electromagnetic switching valve 18 is adjusted (duty ratio control). Based on the opening / closing adjustment, the valve opening pressure of the pressing force adjusting valve 29 and the hydraulic pressure introduced into the hydraulic chamber of the pressing device 14 are adjusted to restrict the pressing force generated by the pressing device 14. . If necessary, the target value, the hydraulic pressure actually introduced into the hydraulic chamber of the pressing device 14, and the opening / closing amount of the electromagnetic valve 18 for line pressure control (control duty [%]). ) Is preferably corrected in accordance with the oil temperature at that time {temperature of lubricating oil (traction oil) circulating in the toroidal type continuously variable transmission 4}. In this case, for example, using the relationship between the target value and the opening / closing amount of the line pressure control electromagnetic opening / closing valve 18 obtained for each oil temperature, the opening / closing amount is adjusted according to the oil temperature at that time ( to correct. With this configuration, the hydraulic pressure actually introduced into the hydraulic chamber of the pressing device 14 is a value corresponding to the traction coefficient at that time and the temperature characteristics of each component (for example, the amount of elastic deformation and the friction coefficient) ( More optimal value). Moreover, the target hydraulic pressure can be introduced regardless of the viscosity change of the lubricating oil. In addition, also when setting a target value (and clutch target value described later) based on the first function described above (and second and third functions described later), it corresponds to the oil temperature at that time point. It is possible to adjust (correct) the opening / closing amount of the line pressure control electromagnetic switching valve 18.

  As described above, in the case of this example, the adjustment of the hydraulic pressure introduced into the pressing device 14 includes the second function {the operation amount of the accelerator device (accelerator opening) and the engine in addition to the first function (differential pressure). 1 can be performed based on the rotational speed of the drive shaft (engine rotational speed). However, in the case of this example, similar to the structure shown in FIGS. 12 to 13 described above, the pressure oil in the primary line 50 regulated by the pressing force regulating valve 29 is used as the pressure reducing valve 38 and the low speed clutch. The clutches are introduced into the low speed and high speed clutches 7 and 8 via the clutch switching valves 25 and 26, respectively. In the case of such a structure, as described above, depending on the relationship between the required loading pressure and the required clutch pressure, that is, within the speed ratio range indicated by K in FIG. Get smaller. In this case, even if the hydraulic pressure introduced into the pressing device 14, that is, the hydraulic pressure of the primary line 50 is adjusted to the required loading pressure based on the first function or the second function, the primary line 50 Is introduced into the low-speed and high-speed clutches 7 and 8 as they are, sufficient hydraulic pressure (required clutch pressure) is not introduced into the hydraulic chambers 52a and 52b of the clutches 7 and 8, There is a possibility that slipping (slipping of the clutch plate) may occur at the fastening portions of the clutches 7 and 8.

  Therefore, in the case of this example, the controller 16 constituting the hydraulic pressure adjusting means is provided with a target value corresponding to the hydraulic pressure to be introduced into the pressing device 14 at that time, and the low speed and high speed clutches. 7 and 8 are compared with the clutch target value corresponding to the hydraulic pressure to be introduced into each of the low speed and high speed clutches 7 and 8, and a larger value is compared with the actual target value (actual target value). ) And the function of adjusting the hydraulic pressure to this target value (actual target value). Therefore, in addition to the first and second functions described above, the controller 16 determines at least the differential pressure value as a clutch target value corresponding to the hydraulic pressure to be introduced into the low speed and high speed clutches 7 and 8. And a fourth function obtained based on at least the operation amount of the accelerator device (accelerator opening) and the rotational speed of the drive shaft of the engine 1 (engine rotational speed). Yes.

  Of these, the third function is to obtain the clutch target value based on the passing torque corresponding to the differential pressure and, for example, the aforementioned equation (1). Further, the fourth function is a function for obtaining the clutch target value by using the output torque corresponding to the operation amount and the rotational speed, and the equation (1), for example. Further, instead of the equation (1), for example, the relationship between the transmission torque (passing torque, output torque) and the hydraulic pressure to be introduced into the low speed and high speed clutches 7 and 8 is obtained by experiment or calculation. A MAP or a diagram can also be used. In this case, in addition to those common to the low speed mode and the high speed mode, those corresponding to the low speed mode (for example, MAP and diagram for low speed mode) and those corresponding to the high speed mode (for example, for high speed mode) It is also possible to use different ones for MAP and diagram).

  In the case of the continuously variable transmission of this example having the first and second functions as described above and the third and fourth functions as described above, it operates in the low speed mode and the high speed mode. The first target value obtained based on the first function, the second target value obtained based on the second function, and the first target value obtained based on the third function The clutch target value is compared with the second clutch target value obtained based on the fourth function, and the largest value is set as the actual target value (actual target value). Adjust the oil pressure to the actual target value. In the case of this example, the clutch 16 is not connected to the controller 16 at the time of mode switching between the low speed mode and the high speed mode, that is, for mode switching. From the controller 16, a command (control signal) to connect the clutch 7 (8) to the clutch switching valve 45 (46) for connecting one clutch 7 (8) is received from the controller 16. Until the other clutch 8 (7) connected so far is disconnected {the clutch is connected to the clutch switching valve 46 (45) for connecting the other clutch 8 (7). 8 (7) until the command (control signal) for disconnection is issued from the controller 16}, only the second target value is compared with the second clutch target value. Value target value and actual target value (actual target value) Set Te, and also functions to have to adjust the hydraulic pressure to the target value (the actual target value).

  The function (loading pressure control) provided in the controller 16 as described above will be described with reference to the flowchart of FIG. The work shown in this flowchart is repeated (automatically) when, for example, the shift lever is operated in the running state (D, L, R range) and the vehicle is running. Note that this operation is not performed when the shift lever is operated in the non-traveling state (N, P range) and the vehicle is stopped (performed as necessary when the shift lever is in the N range and coasting).

  First, in step 1, the controller 16 determines whether or not the current traveling mode is the low speed mode. This determination is made, for example, by determining the switching state (energized state) of the high-speed clutch and low-speed clutch solenoid valves 45 and 46 and the connection / disconnection state of the low-speed and high-speed clutches 7 and 8 at that time. By doing things. If it is determined in step 1 that the current travel mode is the low speed mode, the process proceeds to step 2. In step 2, it is determined whether or not the mode is currently being switched from the low speed mode to the high speed mode. In this determination, for example, in order to connect the low speed clutch 7, the low speed clutch solenoid valve 45 is switched to a state in which pressure oil is introduced into the low speed clutch 7, and the high speed clutch 8. The high-speed clutch solenoid valve 46 is also switched to a state where pressure oil is introduced into the high-speed clutch 8 (a command for switching is issued). Do.

In such step 2, the mode is not currently switched from the low speed mode to the high speed mode, that is, the operation is being performed in the low speed mode (a command to connect the clutch only to the electromagnetic valve 45 for low speed clutch is issued). If it is determined, the process proceeds to step 3. Steps 3 to 7 are necessary for connecting the target value (required loading pressure X _L ) corresponding to the hydraulic pressure to be introduced into the pressing device 14 at that time and the low speed and high speed clutches 7 and 8. The clutch target value (required clutch pressure Y _L ) corresponding to the hydraulic pressure to be introduced into each of the low speed and high speed clutches 7 and 8 is compared, and the larger value among these is the actual target value (actual target value). ). For this purpose, first, in step 3, a target value (necessary loading pressure X _L ) corresponding to the hydraulic pressure to be introduced into the pressing device 14 is obtained (calculated). This calculation is performed according to the procedure shown in FIG.

First, in step 3-1, shown in FIG. 5, the second target value _AL is calculated based on the second function. That is, the second target value _AL is calculated based on the output torque (engine rotational speed, accelerator opening) at that time and the gear ratio of the toroidal continuously variable transmission 4. In Step 3-1, since the vehicle is operating in the low speed mode, the second target value _AL is calculated using, for example, the low speed mode MAP. Step 3-1 In this manner, by using the MAP for the low-speed mode, corresponding to the output torque at the time and the speed ratio, if the calculated the second target value A _L, the following step 3-2 Thus, the first target value _BL is calculated based on the first function. That is, in step 3-2, the first target value _BL is calculated based on the passing torque (differential pressure) at that time and the speed ratio of the toroidal-type continuously variable transmission 4. Even in step 3-2, since the vehicle is operating in the low speed mode, the first target value _BL is calculated using, for example, the low speed mode MAP.

Performs calculation of the second target value A _L based on the second function in step 3-1 as described above, the first target value B _L based on the first function in step 3-2 If the calculation is performed, the first target value B _L and the second target value A _L are compared in subsequent Step 3-3. Specifically, it is determined whether or not the second target value A _L is equal to or greater than the first target value B _L (A _L ≧ B _L ). If it is determined in step 3-3 that the second target value A _L is greater than or equal to the first target value B _L (A _L ≧ B _L ), the process proceeds to step 3-4. Of these, the second target value A _L is set to the required loading pressure X _L and the process ends (proceed to step 4 in FIG. 4). On the other hand, in step 3-3, the second target value A _L is not equal to or greater than the first target value B _L , that is, the second target value A _L is greater than the first target value B _L. If it is determined that the value is smaller (A _L <B _L ), the process proceeds to step 3-5, in which the first target value B _L is set to the required loading pressure X _L and the process ends (see FIG. 4). Go to step 4).

If the required loading pressure _XL is set in step 3 as described above, then in step 4, the clutch corresponding to the hydraulic pressure to be introduced into the clutch device 6, that is, the low speed and high speed clutches 7 and 8, respectively. A target value (required clutch pressure Y _L ) is obtained (calculated). This calculation is performed according to the procedure shown in FIG. First, in Step 4-1 shown in FIG. 6, the second clutch target value C _L is calculated based on the fourth function. That is, the second clutch target value C _L is calculated based on the output torque (engine speed, accelerator opening) at that time. In Step 4-1, since the vehicle is operating in the low speed mode, the second clutch target value C _L is calculated using, for example, the low speed mode MAP. In this way, if the second clutch target value C _L corresponding to the output torque at that time is calculated using the low speed mode MAP in step 4-1, then in step 4-2, the second clutch target value _CL is calculated. The first clutch target value _DL is calculated based on the three functions. That is, in step 4-2, the first clutch target value _DL is calculated based on the passing torque (differential pressure) at that time. Even in step 4-2, since the vehicle is operating in the low speed mode, the first clutch target value _DL is calculated using, for example, the low speed mode MAP.

As described above, the second clutch target value C _L is calculated based on the fourth function in Step 4-1, and the first clutch target value D is calculated based on the third function in Step 4-2. _{If L} is calculated, in the following step 4-3, the first clutch target value _DL and the second clutch target value _CL are compared. Specifically, it is determined whether or not the second clutch target value C _L is equal to or greater than the first clutch target value D _L (C _L ≧ D _L ). If it is determined in step 4-3 that the second clutch target value C _L is greater than or equal to the first clutch target value D _L (C _L ≧ D _L ), the process proceeds to step 4-4. Of these, the second clutch target value C _L is set to the required clutch pressure Y _L and the process ends (proceeds to step 5 in FIG. 4). On the other hand, in step 4-3, the second clutch target value C _L is not greater than or equal to the first clutch target value D _L , that is, the second clutch target value C _L is the first clutch target value. If it is determined that it is smaller than D _L (C _L <D _L ), the routine proceeds to step 4-5, where the first clutch target value D _L is set to the required clutch pressure Y _L and ends. (Proceed to step 5 in FIG. 4).

As described above, the required loading pressure X _L is set in step 3 and the required clutch pressure Y _L is set in step 4 as described above. Then, in step 5, the required clutch pressure Y _L and the required loading pressure are set. Compare X _L. Specifically, it is determined whether or not the required loading pressure X _L is equal to or higher than the required clutch pressure Y _L (X _L ≧ Y _L ). If it is determined in step 5 that the required loading pressure X _L is equal to or higher than the required clutch pressure Y _L (X _L ≧ Y _L ), the process proceeds to step 6 where the required loading pressure X _L is set. Set to the actual target value (actual target value). On the other hand, in step 5, the required loading pressure X _L is not the required clutch pressure Y _L or more, i.e., the required loading pressure X _L is smaller than the required clutch pressure Y _L and (X _L <Y _L) determination If YES, the routine proceeds to step 7, where the required clutch pressure Y _L is set to the actual target value (actual target value). If the actual target value (required loading pressure X _L or required clutch pressure Y _L ) is set in step 6 or step 7 as described above, the process proceeds to step 8, and this actual target value (required loading pressure X _L Alternatively, in order to adjust the hydraulic pressure to the required clutch pressure Y _L ), the opening / closing of the line pressure control electromagnetic on-off valve 18 is adjusted (duty ratio control).

On the other hand, in step 2, the mode is currently being switched from the low speed mode to the high speed mode. That is, not only the low speed clutch electromagnetic valve 45 but also the high speed clutch electromagnetic valve 46 is concerned with the clutch (high speed clutch 8). Is determined to be issued (the low speed and high speed clutches 7 and 8 are simultaneously connected, or the command for that is issued) Proceed to step 9. Steps 9 to 13 include the second target values A _L and A _H obtained based on the second function and the second clutch target value C obtained based on the fourth function at that time. _L and C _H are compared, and the target value having the largest value among them is set as the actual target value (actual target value). For this purpose, first, in steps 9 and 10, the second target value A _{L and} the second clutch target value C _L corresponding to the low speed mode that is the current travel mode are obtained. That is, in step 9, using the low-speed mode for MAP for determining the second target value A _L of the output torque (engine speed, accelerator opening) at the time the toroidal type continuously variable transmission corresponding to the gear ratio of the machine 4, obtaining the second target value a _L. Further, in the subsequent step 10, the second mode MAP for obtaining the second clutch target value C _L is used, and the second torque corresponding to the output torque (engine speed, accelerator opening) at that time is used. The clutch target value C _L is obtained.

Next, in steps 11 and 12, a second target value A _{H and a} second clutch target value C _H corresponding to the high speed mode that is the next running mode to be realized are obtained. That is, in step 11 above, using the high speed mode MAP for obtaining the second target value A _H among them, the output torque (engine speed, accelerator opening) at that time and the toroidal type continuously variable transmission The second target value A _H corresponding to the gear ratio of the machine 4 is obtained. In the subsequent step 12, the second mode MAP for obtaining the second clutch target value C _H is used, and the second torque corresponding to the output torque (engine speed, accelerator opening) at that time is used. The clutch target value C _H is obtained. Then, in the following step 13, the largest target value among the second target values A _L and A _{H and} the second clutch target values C _L and C _H obtained in the above steps 9 to 12 is determined. Set as the actual target value (actual target value). Next, the process proceeds to step 8, and the opening / closing of the line pressure control electromagnetic switching valve 18 is adjusted (duty ratio control) in order to adjust the hydraulic pressure to the actual target value.

On the other hand, if it is determined in step 1 that the current travel mode is not the low speed mode, that is, the current travel mode is the high speed mode, the process proceeds to step 14. Steps 14 to 19 are the same as steps 2 to 7 described above except that the low speed mode and the high speed mode are different {low speed (L) and high speed (H) are reversed}. is there. Step 14 and subsequent steps 20 to 24 are the same as steps 2 and 9 to 13 described above. That is, in the above steps 14 to 19, based on the determination that the vehicle is operating in the high speed mode, in steps 15 and 16, the first target value B is based on the first function as shown in FIGS. _H , the second target value A _H based on the second function, the first clutch target value D _H based on the third function, and the second clutch target value C based on the fourth function _Find each _H. Then, these target values B _H , A _H , D _H and C _H are compared, and the largest value among them is set as the actual target value. In steps 14, 20 to 24, based on the determination that the mode is switched from the high speed mode to the low speed mode, the second target values A _L and A _{H and} the second clutch target values C _L , Of C _H , the largest target value is set as the actual target value (actual target value). In either case, the process proceeds to step 8 to adjust the open / close state of the line pressure control electromagnetic switching valve 18 (duty ratio) in order to adjust the hydraulic pressure to the target value (actual target value) set in this way. Control.

In the case of this example configured as described above, the clutch device 6 to be connected (each of the low speed and high speed clutches 7, while ensuring an appropriate pressing force at the traction portion (rolling contact portion) for transmitting power. The fastening pressure of 8) can be secured.
That is, in the case of this example, during operation, the first and second target values A _L and B _L (A _H and B _H ) corresponding to the hydraulic pressure to be introduced into the pressing device 14 at that time point, The first and second clutch target values C _L and D _L (C _H and D _H ) corresponding to the hydraulic pressure to be introduced into the clutch device 6 (low speed and high speed clutches 7 and 8) are compared. Is set as the actual target value, and the hydraulic pressure is adjusted to the actual target value. Therefore, even when the required loading pressure is smaller than the required clutch pressure, sufficient hydraulic pressure (necessary clutch pressure) is provided in the hydraulic chambers (52a, 52b) of the clutch device 6 (low speed and high speed clutches 7, 8). It is possible to prevent slippage (slipping of the clutch plate) at the engaging portion of the clutch device 6 (low-speed and high-speed clutches 7 and 8). This point will be described below.

As described above, FIG. 9 shows the speed ratio of the entire continuously variable transmission corresponding to the continuously variable transmission of this example and the hydraulic chamber 51 of the pressing device 14 when transmitting the maximum torque. An example of the relationship between the required loading pressure corresponding to the hydraulic pressure and the required clutch pressure corresponding to the hydraulic pressure to be introduced into the hydraulic chambers 52a and 52b of the low speed and high speed clutches 7 and 8 is shown. As is apparent from FIG. 9, in the case of the continuously variable transmission of this example, the required loading pressure is smaller than the required clutch pressure within the range of the speed ratio indicated by K in FIG. However, in this example, as described above, the first and second target values A _L and B _L (A _H , B _H ) and the first and second clutch target values C _L and D _L ( The largest value of C _H and D _H ) is set as the actual target value, and the hydraulic pressure is adjusted to the actual target value. For this reason, as shown by the solid line in the lowermost stage of FIG. 10 and FIG. 11 (control pressure diagram), the hydraulic pressure that is actually adjusted (actual control pressure) is the required loading pressure indicated by the broken line and the chain line. It does not fall below the required clutch pressure. For this reason, it is possible to secure the fastening pressure of the clutch device 6 (low speed and high speed clutches 7 and 8) to be connected while securing an appropriate pressing force at the traction part (rolling contact part) for transmitting power. FIG. 10 schematically shows changes in the state quantities of the respective parts when the mode is switched from the low speed mode to the high speed mode during acceleration with the accelerator pedal depressed. FIG. 11 schematically shows changes in the state quantities of each part when the mode is switched from the high speed mode to the low speed mode during deceleration with the accelerator pedal released.

In the case of this example, as described above, during the mode switching, only the second target values A _L and A _{H and} the second clutch target values C _L and C _H are compared. A large target value is set as the actual target value, and the hydraulic pressure is adjusted to the actual target value. That is, during mode switching, the first target values B _L and B _{H and} the first clutch target values D _L and D _H are not used {the required loading pressure below the solid line (actual control pressure) in FIGS. Do not use the required clutch pressure}. Therefore, as shown in FIGS. 10 to 11, the pressing force generated by the pressing device 14 during mode switching (even when both the low speed and high speed clutches 7 and 8 are simultaneously connected), and The engagement pressure of the clutch device 6 (low speed and high speed clutches 7, 8) can be adjusted to an appropriate value corresponding to the force (power, torque) output from the engine 1 at that time. In addition, when the mode is switched, the pressing force and the fastening pressure are reduced due to the reverse direction of the torque (passing torque) passing through the toroidal type continuously variable transmission 4 (the differential pressure becomes zero, etc.). (Insufficient) can also be prevented. For this reason, in addition to being able to adjust the pressing force and the fastening pressure to appropriate values, unnecessary fluctuations in the pressing force and the fastening pressure can be reduced (the pressing force and the fastening pressure are not greatly changed), It is also possible to reduce the torque shift associated with fluctuations in the pressing force and the fastening pressure.

Further, in the case of this example, during the mode switching, target values A _L and A _{H and} clutch target values C _L and C _H corresponding to the current driving mode and the driving mode to be realized next are obtained. The largest target value is set as an actual target value, and the hydraulic pressure is adjusted to the actual target value. For this reason, as shown in FIGS. 10 to 11, even though the required loading pressure and the required clutch pressure are different before and after the mode switching, the pressing pressure and the fastening pressure from the start of the mode switching to immediately after the completion of the mode switching. Can be surely prevented.

  In the above description, the present invention is combined with a toroidal continuously variable transmission and a planetary gear type transmission, and the rotation state of the output shaft is corrected with the input shaft rotated in one direction. The case where the present invention is applied to a continuously variable transmission equipped with a mode (low speed mode) capable of realizing a so-called geared neutral state that can be switched between rotation and reverse rotation has been described. However, the present invention combines a toroidal type continuously variable transmission and a planetary gear type transmission, a mode in which power is transmitted only by the toroidal type continuously variable transmission (low speed mode), and a planetary gear type which is a differential unit. The present invention can also be applied to a continuously variable transmission having a mode (high speed mode) for realizing a so-called power split state in which main power is transmitted by a transmission and the gear ratio is adjusted by the toroidal type continuously variable transmission. . The structure of the toroidal continuously variable transmission may be either a half toroidal type or a full toroidal type.

The block diagram similar to FIG. 12 which shows an example of embodiment of this invention. FIG. 14 is a hydraulic circuit diagram similar to FIG. 13. The hydraulic circuit diagram similar to FIG. 2 which shows another example. The flowchart which shows the operation | movement used as the characteristic of this invention. The flowchart for calculating | requiring the required loading pressure in low speed mode. The flowchart for calculating | requiring the required clutch pressure in low speed mode. The flowchart for calculating | requiring the required loading pressure in high speed mode. The flowchart for calculating | requiring the required clutch pressure in high speed mode. The diagram which shows the relationship between the speed ratio as the whole continuously variable transmission, the pressing force of a pressing device, and the fastening pressure of a clutch apparatus. The diagram which shows the change of the state quantity of each part at the time of mode switching from low speed mode to high speed mode. The diagram which shows the change of the state quantity of each part at the time of mode switching from high speed mode to low speed mode. The block diagram of the conventional continuously variable transmission. The hydraulic circuit diagram which shows the mechanism for adjusting the gear ratio of the toroidal type continuously variable transmission built in this continuously variable transmission, and the pressing force which a pressing device generate | occur | produces. The diagram which shows one example of the relationship between the opening degree of the electromagnetic on-off valve for line pressure control, and the pressure reduction amount of the valve opening pressure of a pushing pressure regulation valve. The diagram which shows one example of the correlation of the speed ratio as the whole continuously variable transmission, and the gear ratio of a toroidal type continuously variable transmission.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Damper 3 Input shaft 4 Toroidal type continuously variable transmission 5 Planetary gear type transmission 6 Clutch device 7 Low speed clutch 8 High speed clutch 9 Output shaft 10 Input side disk 11 Output side disk 12 Power roller 13 Actuator 14 Press device DESCRIPTION OF SYMBOLS 15 Gear ratio control unit 16 Controller 17 Stepping motor 18 Line pressure control electromagnetic on-off valve 19 Solenoid valve 20 Shifting solenoid valve 21 Control valve device 22 Gear ratio control valve 23 Differential pressure cylinders 24a, 24b Correction control valve 25 High speed clutch Switching valve 26 Low-speed clutch switching valve 27, 27a, 27b Oil pump 28 Oil reservoir 29 Push pressure adjusting valve 30 Low pressure side adjusting valve 31 Manual hydraulic switching valve 32 First pilot portion 33 Second pilot portion 34 Third Pilot part 35 Piston 36a, 36b Oil Chamber 37 Differential pressure take-out valve 38 Pressure reducing valve 39, 39a, 39b Hydraulic sensor 40 Input side rotational speed sensor 41 Output side rotational speed sensor 42 Oil temperature sensor 43 Pilot chamber 44a, 44b Oil path 45 Low speed clutch solenoid valve 46 For high speed clutch Solenoid valve 47 Forward / reverse switching valve 48 Accelerator sensor 49 Engine controller 50 Primary line 51 Hydraulic chamber 52a, 52b Hydraulic chamber

Claims (6)

Toroidal continuously variable transmission and clutch device,
Of these, the toroidal continuously variable transmission includes a first disk and a second disk disposed concentrically and relatively rotatably, and the inner surfaces of the first and second disks facing each other. A plurality of power rollers that are sandwiched and transmit power between the first and second disks, a plurality of support members that rotatably support the power rollers, and each of the support members, An actuator that changes the gear ratio between the first disk and the second disk by displacing in the axial direction of the pivot provided at both ends, and the first disk and the second disk are brought closer to each other. A pressing device that presses in the direction. The pressing device generates a pressing force proportional to the hydraulic pressure with the introduction of the hydraulic pressure, and is used to adjust the hydraulic pressure introduced into the pressing device. oil The adjusting means adjusts the hydraulic pressure to be introduced into the pressing device to a target value corresponding to the pressing force to be generated by the pressing device, which is set according to the state quantity representing the operation status at that time. ,
In the continuously variable transmission, the clutch device is connected based on the introduction of the hydraulic pressure adjusted to the target value by the hydraulic pressure adjusting means.
The hydraulic pressure adjusting means includes the target value corresponding to the hydraulic pressure to be introduced into the pressing device at that time, and the clutch target value corresponding to the hydraulic pressure to be introduced into the clutch device necessary for connection of the clutch device. A continuously variable transmission characterized in that a large value among these is set as an actual target value and the hydraulic pressure is adjusted to this target value. The actuator is hydraulic,
The hydraulic pressure adjusting means includes a first function for obtaining a target value corresponding to the hydraulic pressure to be introduced into the pressing device based on a hydraulic pressure difference between at least one pair of hydraulic chambers provided in the actuator, and at least a toroidal type It has a second function to be obtained based on the operation amount of the accelerator device for adjusting the output of the drive source connected to the continuously variable transmission and the rotational speed of the drive shaft of this drive source, and is introduced into the clutch device. A third function for obtaining a clutch target value corresponding to the hydraulic pressure based on at least a difference in hydraulic pressure between the hydraulic chambers of the actuator; at least an operation amount of the accelerator device; and rotation of a drive shaft of the drive source And a fourth target value obtained based on the first function, and a second target value obtained based on the second function. The first clutch target value obtained based on the third function is compared with the second clutch target value obtained based on the fourth function, and the largest value is compared with the actual target value. Set as a value and adjust the oil pressure to this target value,
The continuously variable transmission according to claim 1. Composed of a toroidal continuously variable transmission and a differential unit through a clutch device,
Of these, the clutch device includes a first clutch that is connected when realizing the first mode for increasing the reduction ratio and is disconnected when realizing the second mode for reducing the same. And a second clutch that is connected when realizing the first mode and disconnected when realizing the first mode.
The continuously variable transmission according to any one of claims 1 and 2. The actuator is hydraulic,
The hydraulic pressure adjusting means includes a first function for obtaining a target value corresponding to the hydraulic pressure to be introduced into the pressing device based on a hydraulic pressure difference between at least one pair of hydraulic chambers provided in the actuator, and at least a toroidal type It has a second function to be obtained based on the operation amount of the accelerator device for adjusting the output of the drive source connected to the continuously variable transmission and the rotational speed of the drive shaft of this drive source, and is introduced into the clutch device. A third function for obtaining a clutch target value corresponding to the hydraulic pressure based on at least a difference in hydraulic pressure between the hydraulic chambers of the actuator; at least an operation amount of the accelerator device; and rotation of a drive shaft of the drive source And a fourth function to be determined based on the speed,
During operation in the first mode or the second mode, the first target value obtained based on the first function, the second target value obtained based on the second function, and the first The first clutch target value obtained based on the third function is compared with the second clutch target value obtained based on the fourth function, and the largest value is set as the actual target value. And adjust the hydraulic pressure to this target value,
The continuously variable transmission according to claim 3. When switching the mode between the first mode and the second mode, the clutch device connects a clutch that has not been connected by one of the first clutch and the second clutch. From the same time, by disconnecting the clutch that was previously connected with the other clutch, the time for both these clutches to be connected at the same time was set.
The hydraulic pressure adjusting means at least sets a target value corresponding to the hydraulic pressure to be introduced into the pressing device, at least an operation amount of the accelerator device for adjusting an output of the driving source connected to the toroidal type continuously variable transmission, and the driving source The second function obtained based on the rotational speed of the drive shaft and the clutch target value corresponding to the hydraulic pressure to be introduced into the clutch device are at least the operation amount of the accelerator device and the rotational speed of the drive shaft of the drive source. With a fourth function based on
When the mode is switched between the first mode and the second mode, the target value obtained based on the second function is compared with the clutch target value obtained based on the fourth function. , Set the target value of the larger value as the actual target value, and adjust the hydraulic pressure to this target value,
The continuously variable transmission according to any one of claims 3 to 4. When the mode is switched between the first mode and the second mode, based on the second function, a target value corresponding to the current travel mode and a target value corresponding to the travel mode to be realized next are obtained. , Respectively, and based on the fourth function, obtain a clutch target value corresponding to the current travel mode and a clutch target value corresponding to the travel mode to be realized next, and obtain these four values. And set the target value of the largest value among them as the actual target value, and adjust the hydraulic pressure to this target value.
The continuously variable transmission according to claim 5.

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